Health Study Activities Frequently Asked Questions (FAQs)
Birth Defects and Childhood Cancers Study
1.What progress has ATSDR made on its study of contaminated drinking water at Camp Lejeune and specific birth defects and childhood cancers?
ATSDR has finalized a study on specific birth defects and childhood cancers. The study includes children born from 1968 through 1985 to mothers who for some time during their pregnancy lived at Camp Lejeune. The study looked at whether children whose mothers were exposed to contaminated drinking water while they were pregnant at Camp Lejeune were more likely to have specific birth defects. The study also looked at whether children exposed to contaminated drinking water in utero or during their first year of life were more likely to have specific childhood cancers. Parents of the children were interviewed in spring/summer 2005 about where they lived at Camp Lejeune from 1968 through 1985, their medical histories, and their personal habits.
2. Why did this study examine only the period from 1968 to 1985?
The study only included children born between 1968 and 1985 because computerized birth certificates in North Carolina became available in 1968 and the heavily contaminated wells on base were shut down in 1985.
3. Which conditions were included in ATSDR's study?
The study included:
- neural tube defects (NTD), consisting of anencephaly (absence of a major portion of the brain) and spina bifida,
- cleft lip and cleft palate,
- and childhood leukemia and non-Hodgkin lymphoma.
4. Why does the study focus only on neural tube defects, oral clefts, childhood leukemia, and childhood non-Hodgkin lymphoma?
ATSDR chose to study these diseases because studies conducted elsewhere suggested that exposures to the chemicals in the Camp Lejeune drinking water might cause these health effects. ATSDR tried to study other birth defects and childhood cancers, but not enough cases were identified during the 1999-2002 survey.
5. How did ATSDR identify the cases of NTDs, cleft lip and palate, and childhood leukemia and non-Hodgkin lymphoma?
There was no cancer or birth defect registry in North Carolina during 1968-1985, so ATSDR had to conduct a phone survey of parents who lived on base during this period to identify cases of these diseases. ATSDR then confirmed the diagnoses of these diseases by obtaining medical records.
6. How did the drinking water at Camp Lejeune get contaminated?
The water system serving the Tarawa Terrace housing area was contaminated by PCE dumped into the environment by an off-base dry cleaner. The Hadnot Point water system serving the main portion of the base (“mainside”) was contaminated by TCE, PCE and benzene from several sources on base including
- leaking underground storage tanks,
- industrial area spills,
- and leaching from a toxic waste dump.
7. Why did it take 8 years after ATSDR completed data collection to analyze and report the findings of this study?
Study researchers had to wait until ATSDR’s water modeling was completed to find out the levels of contaminants in the water systems during 1968-1985. Sample data showing the levels of specific contaminants in the water systems were only available starting in 1982. Therefore, modeling was needed to estimate contaminant levels prior to 1982. We also needed to model the contaminant levels from 1982 onward because of insufficient sampling data. ATSDR completed the study soon after the modeling results were available.
8. What did you find?
Study findings suggested that mothers who had first trimester exposures to drinking water contaminated with TCE at Camp Lejeune were more likely to have a child with a neural tube defect compared with unexposed mothers. The higher the mother’s exposure to TCE, the higher the likelihood that the child would have a neural tube defect. This finding is consistent with a previous study conducted in New Jersey (Bove FJ, et al. Public drinking water contamination and birth outcomes. Am J Epidemiol 1995, 141:850-862).
Study findings also suggested that mothers who had first trimester exposures to drinking water contaminated with benzene were more likely to have a child with a neural tube defect compared with unexposed mothers. However, we could not look at whether higher benzene exposures increased the likelihood of having a child with a neural tube defect because of small numbers of exposed cases.
Mothers with first trimester exposures to PCE, vinyl chloride, or DCE were more likely to have a child with leukemia or non-Hodgkin lymphoma compared with unexposed mothers. However, these findings are weaker than the findings for neural tube defects because higher exposures did not increase the likelihood that the child would have these cancers.
9. What is different about this study?
ATSDR’s study is unique because we were able to model the average monthly levels of the contaminants in the drinking water. We used these data to find out whether mothers exposed to these contaminants during pregnancy were more likely to have a child with a specific birth defect or childhood cancer. This effort included assessment of contaminant levels from the source to the residences averaged on a monthly basis.
There is little information in the scientific literature on whether maternal drinking water exposures to the contaminants at Camp Lejeune are linked to birth defects and childhood cancers. Very few studies have focused on the health effects of maternal drinking water exposures. Most studies in the literature have focused on the health effects of workplace exposures to mothers.
ATSDR’s water modeling approach is unique for its complexity. We needed to determine how the chemicals moved from the locations where they entered the environment through groundwater to drinking water supply wells and then into the distribution system. The modeling estimated monthly mean concentrations for specific VOCs—PCE, TCE, trans-1,2-DCE, vinyl chloride, and benzene. We needed monthly estimates so that we could estimate exposures during specific pregnancy trimesters.
10. How does this study help?
This study makes an important contribution to the scientific knowledge about the health effects of these chemicals. Information from this study, along with other information about the health effects of these chemicals, will help with policy and regulatory decisions about regulating these contaminants in drinking water.
11. What does this study mean for those pregnant women and their children who were exposed to VOCs at Camp Lejeune?
For mothers and their children who were exposed to the contaminated drinking water at Camp Lejeune, this study may add to their knowledge and understanding about the health effects of these exposures.
12. Why does the study use the word “suggest” instead of a stronger word?
It is hard to be definitive with one study, especially when that study has small numbers of exposed cases.
13. Why didn’t you see an association between benzene and childhood cancer?
We did not see an association between benzene and childhood cancers in this study, but that does not mean that benzene does not cause childhood cancer. It only means that we did not find evidence in this study. There is a gap in the scientific literature about whether benzene is associated with childhood hematopoietic cancers.
Reasons why we didn’t see an association may include:
- The levels of benzene were too low
- Biases, such as exposure misclassification, may have influenced the results
- There were small numbers of exposed benzene cases
- There may not be an association between benzene and childhood hematopoietic cancers
14. Does this study provide evidence of causality?
This study provides some evidence; however, the evidence is not strong for the following reasons:
- Small numbers of exposed cases make it difficult to evaluate exposure-response trends.
- Small numbers of exposed cases result in wide confidence intervals, so there is considerable uncertainty about the actual risk (it could be much higher or much lower).
- This study, like other environmental and occupational studies, is subject to errors in determining people’s exposures and other possible biases which add uncertainty to the results.
- Because there are so few studies in the literature, it is not possible to be definitive about causality. However, once more studies are conducted that find similar results as this study, the evidence may be stronger for causality.
Health Survey Information
1. Why are you doing the health survey?
On January 28, 2008, President Bush signed the 2008 National Defense Authorization Act. This required ATSDR to develop a health survey of persons possibly exposed to contaminated drinking water at Camp Lejeune.
2. Who was eligible for the survey?
Anyone who lived or worked at Camp Lejeune during the period of drinking water contamination was eligible for the survey. ATSDR couldn't identify all of these people from available records, so we sent the survey to the people we could identify.
People who received the survey included:
- former active duty marines and sailors who were stationed at Camp Lejeune anytime between April 1975 and December 1985
- civilian employees who worked at the base anytime between October 1972 nd December 1985
- People who took part in ATSDR’s 1999-2002 survey
- a sample of former active duty and civilian workers from Camp Pendleton
- people who requested a health survey by registering with the United States Marine Corps before June 30, 2011
3. Why did you survey former active duty and civilian workers from Camp Pendleton?
Active duty and civilians who worked at Camp Pendleton and Camp Lejeune are similar except for their exposures to chemicals in drinking water. The information from those who lived at Camp Pendleton allows us to compare the health experiences between these two groups. This will help us determine if contaminated drinking water at Camp Lejeune affected people’s health.
4. What conditions did the health survey ask about?
The health survey asked questions about more than twenty different cancers and other diseases. People also had space to report other diseases not mentioned in the survey.
5. When was the survey sent?
The surveys were mailed from June 2011 through June 2012.
6. Why didn’t I get a survey?
You may not have received a survey because you are not part of one of the groups included in the health survey. The following groups were included in the health survey:
- former active duty marines and sailors who were stationed at Camp Lejeune anytime during April 1975 and December 1985
- civilian employees who worked at the base anytime during October 1972 to December 1985
- people who took part in ATSDR’s 1999-2002 survey
- a sample of former active duty and civilian workers from Camp Pendleton
- people who requested a health survey by registering with the USMC by June 30, 2011
Even if you did not receive a survey, if you lived or worked at one of the bases during this time, the results will apply to you.
7. When will the survey results be available?
We expect to release the survey findings in 2014. Until then, we will be collecting, analyzing and scientifically verifying the diseases reported by participants.ATSDR will make survey results available through a variety of ways. The findings of the survey also will be published in a peer-reviewed scientific journal. ↑back to top
What is the purpose of the study?
The purpose of this study was to determine whether residential exposures of Marine and Naval personnel to contaminated drinking water at Camp Lejeune increased risk of mortality from cancers and other chronic diseases.
What was studied?
The study evaluated specific causes of death in 154,932 Marines and Navy personnel who began service during 1975-19851 and were stationed at Camp Lejeune anytime during this period. We also evaluated a comparison group of 154,969 Marines and Navy personnel from Camp Pendleton. The Camp Pendleton group was not exposed to contaminated drinking water, but was otherwise similar to the Camp Lejeune group.
Cause of death data from 1979-2008 was used to study the Camp Lejeune and Camp Pendleton cohorts. Information on causes of death was obtained from the National Center for Health Statistics National Death Index (NDI). The study included all underlying causes of death that other studies have shown associations with one or more of the chemicals found in the drinking water at Camp Lejeune. Causes of death were selected based on literature reviews conducted by the U.S. Environmental Protection Agency (EPA), the National Toxicology Program (NTP), the International Agency for Research on Cancer (IARC), and ATSDR.
The causes of death studied include:
- Amyotrophic lateral sclerosis (ALS)
- Cancers of the bladder, brain, cervix, colon, esophagus, female breast, kidney, larynx, liver, lung, oral cavity, pancreas, prostate, rectum, and soft tissue
- Hematopoietic cancers
- Hodgkin’s Lymphoma
- Multiple sclerosis
- Non-Hodgkin’s lymphoma
- Non-cancerous kidney diseases
- Non-cancerous liver diseases
- Multiple sclerosis
Also included in the study were three causes of death that are known to be caused by cigarette smoking but are not known to be associated with the drinking water contaminants: stomach cancer, cardiovascular disease, and chronic obstructive pulmonary disease (COPD). These causes of death were included to assess the possible impact of smoking on the findings because we did not have information on smoking status for study subjects.
Why does this study include only Marines and Navy personnel who began service during 1975-1985?
Unit information was needed to determine where the Marines or Navy personnel were stationed. ATSDR could only include Marines and Navy personnel who began service during 1975-1985 and who were stationed at either Camp Lejeune or Camp Pendleton during this timeframe because unit information first became available from the Defense Manpower Data Center (DMDC) personnel database in the second quarter of 1975. Also, the most heavily contaminated wells were shut down in 1985.
Why was Camp Pendleton used as the comparison cohort (population)?
To determine if the contaminated drinking water at Camp Lejeune posed a health risk, it was necessary to select a cohort of Marines and Navy personnel unexposed to contaminated drinking water but similar to the Camp Lejeune on socioeconomic and other risk factors (e.g., smoking and alcohol consumption). For this reason, a cohort from Camp Pendleton was selected.
What did you find?
Compared to Camp Pendleton, the Camp Lejeune group had higher mortality rates for the following causes of death:
- Cancers of the cervix, esophagus, kidney, liver, lung, pancreas, prostate, rectum, and soft tissue
- Hodgkin’s lymphoma
- Multiple myeloma
- Multiple sclerosis
The higher rates for kidney cancer, cervical cancer, Hodgkin’s lymphoma, leukemias, multiple myeloma, and lung cancer were mainly among those with higher cumulative exposures to the contaminants. However, the precision of the estimated rates of many of these conditions was low.
The findings for the smoking-related causes of death such as stomach cancer, cardiovascular disease, and (COPD) suggested that smoking would have only a slight impact on the associations between causes of death and exposure to the drinking water contaminants at Camp Lejeune.
Does this study provide evidence of causation?
This study makes an important contribution to the scientific literature; however it does not provide definitive evidence for causality due to the following limitations:
- Small numbers of specific causes of death resulting in wide confidence intervals, so there is considerable uncertainty about the actual risk (it could be higher or lower).
- Short exposure durations in some cases that likely reduced the magnitude of the effects.
- • Exposure misclassification resulting from:
- Uncertainty about base assignments.
- Limited availability of data on barracks or housing locations.
- Inability to accurately capture time spent away from the base for training or deployment.
- Disease misclassification bias (both false positives and false negatives) is also a possibility.
- Lack of information on other exposures or risk factors
Why is ATSDR doing these studies?
ATSDR is conducting studies about Camp Lejeune because people were exposed to chemicals shown to be associated with several cancers and other chronic conditions. However, the scientific literature is limited on health effects of drinking water exposure to these chemicals. This study was specifically conducted to determine whether drinking water exposures at Camp Lejeune increased risk of mortality from cancers and other chronic conditions. Because of the study’s limitations, it does not provide definitive evidence for causality nor can it answer the question whether an individual has been affected by these exposures at Camp Lejeune. However, it does add to the body of knowledge about potential adverse health effects resulting from exposure to these chemicals via drinking water.↑back to top
Male Breast Cancer Study
1. Why is ATSDR doing a male breast cancer study?
ATSDR is conducting the male breast cancer study to address a concern expressed by members of the Camp Lejeune Community Assistance Panel (CAP) related to the number of cases of breast cancer in males who lived or worked on the base when the water was contaminated. This study aims to examine whether there is a relation between exposure to drinking water contaminated with volatile organic compounds (VOCs) at the U.S. Marine Corps Base, Camp Lejeune and male breast cancer.
Currently, the cause of male breast cancer is unknown, and there is limited scientific research on the relationship between the VOCs in the drinking water at Camp Lejeune and male breast cancer. Scientific support for the study comes from research conducted in Cape Cod, Massachusetts which suggests a relationship between exposure to VOC contaminated drinking water and female breast cancer (1, 2, 3).
2. Why does this study focus only on male breast cancer?
This study focuses on male breast cancer because there is very limited information on the cause of breast cancer among men. The lack of scientific information on the disease is in part due to the uncommon occurrence of the disease among men. For every 1,000 cases of breast cancer in the United States about 7 occur among men. ATSDR’s male breast cancer study aims to further the scientific understanding of the disease by investigating whether exposure to VOCs in the drinking water at Camp Lejeune is associated with developing this uncommon disease.
3. Who is included in the study?
Those included in the study will be selected from the Department of Veteran’s Affairs (VA) Central Cancer Registry. The VA’s cancer registry maintains information from eligible veterans who were diagnosed with cancer or were treated for cancer at a VA clinic. Eligible study members are male Marines born before January 1, 1969 and diagnosed with cancer or treated for cancer at a VA medical facility from January 1, 1995, (the start of the VA’s Central Cancer Registry) to the latest date that complete medical records are available.
4. How will the study be conducted?
The study will be conducted using a case-control design. This design is useful for investigating uncommon diseases such as male breast cancer. The study compares cases to controls looking for differences in exposure levels and the occurrence of disease. Cases are all eligible study members diagnosed with male breast cancer. Controls are randomly selected from the remaining eligible study members not diagnosed with male breast cancer. ATSDR will determine whether cases were more likely than controls to live in housing areas known to have higher levels of VOC in the drinking water supply.
5. What are some of the limitations of this study?
One limitation with this study, specific to the case-control study design, is reliance on historical data to determine exposure to VOC in the drinking water supply. The exact level of exposure is not available for each individual who resided or worked on the base during the period that VOC contamination was in the drinking water at Camp Lejeune, and the level of VOC contamination in the drinking water supply varied by location on the base.
To address this potential limitation, ATSDR estimated VOC contamination levels among the different housing areas on the base. The study will assign exposure levels to each case and control on the basis of residential location and the period of time the study participant was stationed on base. From this information, ATSDR will evaluate whether the contaminated drinking water at Camp Lejeune is related to male breast cancer.
6. Why does the study include only male Marines and not their dependents or civilian employees?
The study includes only male Marines and not their dependents or civilian employees because the VA’s cancer registry is not available for military dependents that lived at Camp Lejeune or civilian workers employed on the base. The VA cancer registry provides the most up to date and accurate information enabling us to conduct this study and facilitate the identification of Marines who served during the time when the water was contaminated. ATSDR is using 2011 health survey data to conduct other health studies that include breast cancer among females who were active duty military members or civilians who worked at Camp Lejeune during the time when the water was contaminated.
7. When will the study results be available?
ATSDR expects to submit the study findings for publication in 2015.
- Aschengrau, A., Paulu, C., & Ozonoff, D. (1998). Tetrachloroethylene-contaminated drinking water and the risk of breast cancer. Environmental health perspectives, 106(Suppl 4), 947.
- Aschengrau, A., Rogers, S., & Ozonoff, D. (2003). Perchloroethylene-contaminated drinking water and the risk of breast cancer: additional results from Cape Cod, Massachusetts, USA. Environmental health perspectives, 111(2), 167.
- Ozonoff, A., Webster, T., Vieira, V., Weinberg, J., Ozonoff, D., & Aschengrau, A. (2005). Cluster detection methods applied to the Upper Cape Cod cancer data. Environmental Health, 4(1), 19.
1997 Public Health Assessment (PHA)
1. Why did the 1997 PHA not mention benzene was present in well 602?
The 1997 PHA does mention benzene in Appendix B (page B-2-4). It does not mention or discuss benzene in the main body of the PHA because we assumed, incorrectly at the time, that well # 602 was not used to supply contaminated drinking water to residents of Camp Lejeune.
2. Why did ATSDR remove the 1997 PHA from the ATSDR Camp Lejeune website?
In the time since the 1997 PHA was published, additional information emerged related to exposures to volatile organic compounds in drinking water at Camp Lejeune. Due in part to ATSDR’s ongoing extensive water modeling and exposure reconstruction study, we learned that communities serviced by the Holcomb Boulevard distribution system were exposed to contaminated water for a longer period than we knew in 1997. Also, at the Camp Lejeune site, benzene was present in one drinking-water supply well in the Hadnot Point drinking water system. That well was shut down sometime prior to 1985. This information should have been included in the PHA but was not. The PHA should have mentioned the contamination and stated that the extent of exposure to benzene from that well was unknown.
3. When will the revised PHA be available?
ATSDR is working to revise the PHA based on available data and input from the Camp Lejeune Community Assistance Panel. The revised PHA will include an updated evaluation of the drinking water exposure pathway and a new evaluation of the vapor intrusion exposure pathway. Once complete, the revised PHA will undergo peer review and be made available for public comment. In the meantime, we continue to stand behind the information related to the other nine pathways that are discussed in the 1997 PHA.↑back to top